Objective:To investigate the expression levels of OPG,RANKL,RANK,and the level and activity of NF-κB p65 in patients with non-small cell lung cancer(NSCLC),then to explore their clinical significance. Methods:The gene expression levels of OPG,RANKL,RANKwere assessed by real-time PCR and the level and activity of NF-κB by western blot in cancer and corresponding adjacent lung tissues of 32 NSCLC patients and normal lung tissues of 15 chest trauma or inflammation patients matched. Results:A significant increasing gradient of gene expression of OPG,RANKL,RANK and RANKL/OPG ratio was identified in normal,adjacent lung tissues of NSCLC and cancer tissues,as well as the intranuclear/total ratio of NF-κB p65,whereas the level of total NF-κB p65 was comparable among the three groups. Moreover,the mRNA levels and RANKL/OPG ratio of the axis in cancer tissues of NSCLC with lymph node metastasis was significantly higher than that in NSCLC without lymph node metastasis. The intranuclear/total ratio of NF-κB p65,but not the total level,was also increased notably in cancer tissues of NSCLC with lymph node metastasis. Conclusion:The activation of OPG/RANKL/RANK axis may play an important role in pathogenesis and lymphatic metastasis of human NSCLC through activating the NF-κB signal transduction pathway.